0
$\begingroup$

This is a practice question that I am trying. I am a student learning about material balance-

enter image description here

I am trying to find the mass composition of stream D. The one written in pencil is the values that I have found in advanced-

My attempt-

I have made a material balance around separator 2 ignoring the recycle stream,

enter image description here

I done up a component X balance-

$1250 X + (120 \times 0.3) = (379.08 \times 0.374) + (90.92 \times 0.222) $

I solve for x $= 0.10076$

Similarly,I done up a component Y balance-

$125 Y + (120 \times 0.7) = (379.08\times0.626) + (90.92\times 0.778)$

I solve for Y $= 0.1792$

I know this is wrong as the composition of X and Y total does not add up to 1. Where did I go wrong or what must I do ?

$\endgroup$
1
$\begingroup$

How do you get D = 1250?

Should it be A + B - C ie 450 + 130 - 230 = 350 based on separator 1 only, ie what leaves separator 1.

Then when you include separator 2 the +900 will give 1250 arriving at separator 2.

$\endgroup$
1
  • $\begingroup$ Oh.., i spotted my mistake.. should not use 1250 which is (350+900) if I am ignoring the recycle stream. Thanks ! $\endgroup$
    – user185692
    Feb 22 '18 at 5:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.